3i6 



NAiURE 



LJa^uary 4, 



IJ ! 



the harmonic constants tabulati-d, but the followmK 

 arc some conclusions which may bo drawn. 



On the Pacific coast the diurnal and semi-diurnal 

 tid«s arc both nearly "inverted," and the tide-wave 

 reaches the north-easterly parts of the islands some- 

 what earlier than the south-westerly coasts. The 

 diurnal ineciuality is large. The Japanese Sea is 

 almost a lake, and it is natural that the range of 

 tide on the western coast should be much less than 

 on the east; it is, in fact, only about one-seventh as 

 )^'reat. But the phases of the tides are pu/zling, for 

 it is diurnal high-water almost simul- 

 taneously throughout the Japanese Sea at 

 the same time that it is diurnal low-water 

 on the Pacific coast, and the diurnal ampli- 

 tudes are not verv different throughout. 

 On the other hand, the semi-diurn.-il 

 phases on the west are so diverse that it 

 IS not easy to interpret their meanings. 

 :md there is some diminution of nmplituci. 

 to the north. If the Straits of Korea ar( 

 wide enough to admit the diurnal wnv 

 SO freely, why is the semi-diurnal tide ^ 

 much broken up? These questions deserv 

 more attention than 1 am able to give i 

 them. 



It seems a pity that in the tables ot 

 harmonic constants the heights should b< 

 given to one-tenth of a millimetre, and tin 

 phases to the hundredth of a degree, fi ; 

 this degree of accuracy is quite fictitious 

 as may be seen by a" comparison of thr 

 values at anv port for successive years. 

 It may be well also to direct attention to 

 the values of the phases assigned to the 

 tides Mj and O for the port of Tonoura 

 for the year 1895. There must be a mis- 

 take, because for that year they are 

 entered as being almost 180° different 

 from the values for all the successive 

 years. There is no misprint, because the 

 suspicious numbers have been used in 

 forming the mean values of M, and O. 

 It is clear from the values assigned to 

 these tides at other ports th.nt i8q5 was 

 not an abnormal year — and "indi-* d such 

 an amount of abnormality would have 

 been nearly incredible. No doubt the 

 source of error will easily be discovered. 



The tidal constants round the Japanese 

 coasts have now been accurately deter- 

 mined, and Prof. Hirayama deserves 

 warm acknowledgment for the care which 

 he has bestowed on his laborious and use- 

 ful task. G. H. Darwin. 



¥lSn PHOTOGRAPHY.' 



T^R. WARD'S book consists really of 

 *-^ a fine series of photographs illus- Fk- »• 



trated by a rather inadequate text. 

 Considerable trouble has been taken by the 

 author to represent British marine and fresh-water 

 fishes as they would be seen by a human observer 

 placed in much the same conditions as the fishes 

 themselves. Many, for instance, were taken from an 

 observation chamber built below the surface of water 

 in a shallow pond, and others have been made from 

 fishes living in tanks, lighted in various ways. The 

 author gives a good account of these methods, which 

 may be of assistance to those engaged in original 

 work. The book also includes a number of micro- 



1 " Marvels of Fish Life as Revealed by the Camera." By Dr. F. Ward. 

 Pp. xiv+t96+plates. (Ixindon: Ca«seM and Co., Ltd., ijit.) Price 6f. 



ph(»tographs of eggs and larvae of both fresh-water 

 and marme fishes, and some of the«.- .irr novel. 



The author tells us, in his intr that h' 



has endeavoured to show how fi- !•-<■ their 



mental sUtes in their attitudes and c- 

 The psychology of the pike and perch- < 

 mental agitation, the rigidity of excitcnieiu, i: 

 disappointment, disgust, alarm, &c.— are reveal* < 

 Dr. Ward, at all events) by these attitudes, 

 interpretations may well be doubted, but the ]>' 

 graphs themselves are interesting and b ' ' 



Klo. I. — l>;moii Sule seen atjainsl a white background, from 



-The same fish in natural surroundings. From ' M.ir\ c'< of Ki^h Life. 



I author is more successful in his illustration of conceal- 

 ment-devices. Thayer's principle of counter or 



I obliterative shading is extended to fishes. Th- 

 darkening of the dorsal, and the lightening of th- 



j ventral surface produce, in a fish lit from above, : 



I flat, ghost-like effect, well shown in the photograpi 



i of the dace on p. 26. The fusion of colour patterns 



{ with that of the background is illustrated by fine 



I photographs of lemon sole and thornback ray lying 



I on the sea bottom. A further device, imperfectly 



I elaborated by the author, is the concealing effect of 



j the reflection of light from silver)- fishes, and the 



I similar effect of the confusion of the iridescence of 



NO. 2201, VOL. 88] 



